ain-util

A collection of utility functions for AI Network (AIN). The methods and tests have been modified from ethereumjs-util and ethjs-util.

Installation

npm install @ainblockchain/ain-util

Examples

const ainUtil = require('@ainblockchain/ain-util');

const message = { foo: 'bar' };
const privateKey = YOUR_OWN_PRIVATE_KEY;

// Alice generates signature using private key.
const signature = ainUtil.ecSignMessage(JSON.stringify(message), Buffer.from(privateKey, 'hex'));

// Bob verifies the message
const hash = ainUtil.hashMessage(JSON.stringify(message));
const sigBuffer = ainUtil.toBuffer(signature);
const len = sigBuffer.length;
const lenHash = len - 65;
const { r, s, v } = ainUtil.ecSplitSig(sigBuffer.slice(lenHash, len));
const publicKey = ainUtil.ecRecoverPub(Buffer.from(hash, 'hex'), r, s, v);
const address = ainUtil.toChecksumAddress(ainUtil.bufferToHex(ainUtil.pubToAddress(publicKey, publicKey.length === 65)));
const isVerified = ainUtil.ecVerifySig(JSON.stringify(message), signature, address);
// console.log(isVerified);
// will return
// ADDRESS
// true

API

addHexPrefix(str: string) -> string

Adds "0x" to a given string if it does not already start with "0x".

bufferToHex(buf: Buffer) -> string

Converts a Buffer into a hex string.

ecSignMessage(message: any, privateKey: Buffer, chainId?: number) -> string

Signs a message with a private key and returns a string signature.

ecRecoverPub(msgHash: Buffer, r: Buffer, s: Buffer, v: number, chainId?: number) -> Buffer

ECDSA public key recovery from signature.

ecSplitSig(signature: Buffer) -> ECDSASignature

Converts signature format of the eth_sign RPC method to signature parameters.

ecVerifySig(data: any, signature: string, address: string, chainId?: number) -> boolean

Checks if the signature is valid.

ecSignTransaction(txData: TransactionBody, privateKey: Buffer, chainId?: number) -> string

Signs a transaction body with a private key and returns a string signature.

hashTransaction(transaction: TransactionBody | string) -> Buffer

Generates keccak hash using a transaction body.

hashMessage(message: any) -> Buffer

Returns the bitcoin's varint encoding of keccak-256 hash of message, prefixed with the header 'AINetwork Signed Message:\n'.

isHexPrefixed(str: string) -> boolean

Checks whether the str is prefixed with "0x".

isValidPrivate(privateKey: Buffer) -> boolean

Checks whether the privateKey is a valid private key (follows the rules of the curve secp256k1).

isValidPublic(publicKey: Buffer, isSEC1: boolean = false) -> boolean

Checks whether the publicKey is a valid public key (follows the rules of the curve secp256k1 and meets the AIN requirements).

isValidAddress(address: string) -> boolean

Checks if the address is valid.

areSameAddresses(address1: string, address2: string) -> boolean

Checks if the two addresses are the same.

keccak(input: any, bits: number = 256) -> Buffer

Creates Keccak hash of the input.

privateToPublic(privateKey: Buffer) -> Buffer

Returns the public key of a given private key.

pubToAddress(publicKey: Buffer, isSEC1: boolean = false) -> Buffer

Returns the AI Network address of a given public key.

privateToAccount(privateKey: Buffer) -> Account

Returns an Account with the given private key.

serialize(data: any, _fields?: Array) -> Buffer (will deprecated)

Serializes an object (e.g. tx data) using rlp encoding.

setLength(message: any, length: number, right: boolean = false) -> Buffer

Pads and message with leading zeros till it has length bytes. Truncates from the beginning if message is longer than length.

stripHexPrefix(str: string) -> string

Removes '0x' from a given String is present.

toBuffer(v: any) -> Buffer

Attempts to turn a value into a Buffer. As input it supports Buffer, String, Number, null/undefined, BN and other objects with a toArray() method.

toChecksumAddress(address: string) -> string

Returns a checksummed address.

encryptWithPublicKey(publicKey: string, message: string) -> Promise

Encrypts message with publicKey.

decryptWithPrivateKey(privateKey: string, encrypted: Encrypted | string) -> Promise

Decrypts encrypted data with privateKey.

createAccount(entropy?: string) -> Account

Creates an account with a given entropy.

privateToV3Keystore(privateKey: Buffer, password: string, options: V3KeystoreOptions = {}) -> V3Keystore

Converts an account into a V3 Keystore and encrypts it with a password.

v3KeystoreToPrivate(v3Keystore: V3Keystore | string, password: string) -> Buffer

Returns a private key from a V3 Keystore.

encode(key: string) -> string

decode(key: string) -> string

Environments

Tested on the below environments.

node

• v12.x.x
• v10.x.x

• v6.x.x
• v7.x.x

LICENSE

MPL-2.0